EP0350934B1 - Appareil d'affichage à cristaux liquides - Google Patents

Appareil d'affichage à cristaux liquides Download PDF

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Publication number
EP0350934B1
EP0350934B1 EP89112877A EP89112877A EP0350934B1 EP 0350934 B1 EP0350934 B1 EP 0350934B1 EP 89112877 A EP89112877 A EP 89112877A EP 89112877 A EP89112877 A EP 89112877A EP 0350934 B1 EP0350934 B1 EP 0350934B1
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EP
European Patent Office
Prior art keywords
electrodes
liquid crystal
scanning
selection signal
pixels
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP89112877A
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German (de)
English (en)
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EP0350934A3 (fr
EP0350934A2 (fr
Inventor
Akira Tsuboyama
Akiko Ooki
Hiroshi Inoue
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Canon Inc
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Canon Inc
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Publication of EP0350934A2 publication Critical patent/EP0350934A2/fr
Publication of EP0350934A3 publication Critical patent/EP0350934A3/fr
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Publication of EP0350934B1 publication Critical patent/EP0350934B1/fr
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Classifications

    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G09G3/3611—Control of matrices with row and column drivers
    • G09G3/3622—Control of matrices with row and column drivers using a passive matrix
    • G09G3/3629—Control of matrices with row and column drivers using a passive matrix using liquid crystals having memory effects, e.g. ferroelectric liquid crystals
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00—Command of the display device
    • G09G2310/02—Addressing, scanning or driving the display screen or processing steps related thereto
    • G09G2310/0224—Details of interlacing
    • G09G2310/0227—Details of interlacing related to multiple interlacing, i.e. involving more fields than just one odd field and one even field
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00—Command of the display device
    • G09G2310/02—Addressing, scanning or driving the display screen or processing steps related thereto
    • G09G2310/0232—Special driving of display border areas
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00—Command of the display device
    • G09G2310/06—Details of flat display driving waveforms
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00—Command of the display device
    • G09G2310/06—Details of flat display driving waveforms
    • G09G2310/061—Details of flat display driving waveforms for resetting or blanking
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00—Command of the display device
    • G09G2310/06—Details of flat display driving waveforms
    • G09G2310/065—Waveforms comprising zero voltage phase or pause
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/02—Improving the quality of display appearance
    • G09G2320/0247—Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G09G3/3611—Control of matrices with row and column drivers
    • G09G3/3685—Details of drivers for data electrodes

Definitions

  • the present invention relates to a liquid crystal apparatus, particularly one using a ferroelectric liquid crystal.
  • Clark and Lagerwall have disclosed a surface-stabilized bistable ferroelectric liquid crystal in Applied Physics Letters, Vol. 36, No. 11 (June 1, 1980), p.p. 889 - 901, and U.S. Patent Publications US-A-4,367,924 and 4,563,059.
  • the bistable ferroelectric liquid crystal has been realized by disposing a chiral smectic liquid crystal between a pair of substrates which are set to provide a spacing small enough to suppress the formation of a helical arrangement of liquid crystal molecules inherent to the bulk chiral smectic phase of the liquid crystal and aligning vertical molecular layers each composed of a plurality of liquid crystal molecules in one direction.
  • a display panel comprising such a ferroelectric liquid crystal may be driven by a multiplexing drive scheme as disclosed by, e.g., U.S. Patent Publication US-A-4,655,561 to Kanbe, et al., to provide a display with a large number of pixels.
  • a ferroelectric liquid crystal as described above shows a responsive time which depends on the surrounding temperature, so that a driving pulse duration at a lower temperature is required to be longer than at a higher temperature.
  • a drive frequency for forming one picture (frame frequency) is lowered at a lower temperature and generally lowered to a frame frequency as low as 1 - 30 Hz. For this reason, a display at a lower temperature is liable to cause "flickering" to provide a display image of a poor display quality.
  • GB-A-2 185 614 discloses a liquid crystal apparatus with scanning electrodes and data electrodes intersecting each other, and a ferroelectric liquid crystal placed therebetween. All pixels, i.e. the intersections of the scanning electrodes and data electrodes, of one selected scanning line are initialized before starting the writing operation. The initialization state can be determined to be "dark” or "white”. The scanning electrodes are selected and driven one after the other in the order as they are positioned in the liquid crystal apparatus.
  • EP-A-0 229 647 a liquid crystal apparatus with scanning electrodes and data electrodes intersecting each other, and a ferroelectric liquid crystal disposed therebetween is known. Moreover, this apparatus comprises driving means for applying a scanning selection signal to the scanning electrodes and data signal to the signal electrodes. All pixels, i.e. the intersections of the scanning electrodes and the data electrodes, on a whole picture area (comprising a plurality of scanning lines) are once initialized into one state. Then some pixels are selectively written into the other state.
  • JP-A-61 272 724 discloses a liquid crystal display device wherein flickering is prevented by means of plural interlaced scanning of the scanning electrodes.
  • An object of the present invention is to provide a liquid crystal apparatus having solved the aforementioned problems, particularly the occurrence of flickering.
  • a liquid crystal apparatus comprising: a liquid crystal device comprising a group of first electrodes, a group of second electrodes intersecting said first electrodes, and a ferroelectric liquid crystal assuming one orientation state in response to an electric field of one polarity and another orientation state in response to an electric field of the other polarity disposed between said group of first electrodes and said group of second electrodes so as to form a picture area comprising a pixel at each intersection of said first and second electrodes; and drive means for sequentially applying a scanning selection signal to said first electrodes and for simultaneously applying data signals to said second electrodes: characterized in that said drive means sequentially apply said scanning selection signal to said- first electrodes for interlaced scanning with an interlacing factor N+1, N being a positive integer such that said scanning selection signal is applied to every (N+1)th electrode in one scanning series so as to form one picture in N+1 scanning series, and simultaneously apply said data signals in synchronism with said scanning selection signal to all or a prescribed part of said second
  • FIG. 1 is a block diagram of an apparatus according to the present invention.
  • Figure 2 is a schematic plan view of a matrix electrode structure used in the present invention.
  • Figure 3 shows a set of drive signal waveforms for multiplexing drive used in the present invention
  • Figure 4 shows a drive signal waveform of a comparative scanning selection signal.
  • Figures 5 and 7 respectively show another set of drive signal waveforms for multiplexing drive used in the present invention.
  • Figure 6 is a schematic plan view of another matrix electrode structure used in the present invention.
  • Figures 8 and 9 are schematic perspective views for illustrating ferroelectric liquid crystal cells used in the present invention.
  • FIG. 1 is a block diagram of a liquid crystal apparatus according to the present invention.
  • the apparatus includes a liquid crystal device, i.e. a liquid crystal display panel 11, for providing a picture area or screen which comprises an image display area 11A for forming an image depending on data signals and a marginal region 11B which is a non-display region for not displaying an image.
  • the liquid crystal display panel 11 is constituted by a ferroelectric liquid crystal and is provided with a drive means, i.e. a drive unit, therefore comprising a scanning drive circuit 12 and a data/margin a data drive circuit 13 which may in turn comprise a data drive circuit 13A and a margin drive circuit 13B.
  • the image display region 11A may be driven by the scanning drive circuit 12 and the data drive circuit 13A and the marginal region(s) 11B may be driven by the scanning drive circuit 12 and the margin drive circuit 13B.
  • the scanning drive circuit 12 supplies scanning selection signals S1, S2, S3, ...
  • the data/margin drive circuit 13 supplies data signals I1, I2, I3, ... and data signals for marginal display W1, W2, W3 ...
  • the scanning drive circuit 12 and the data/margin drive circuit 13 are respectively addressed by a means for controlling, i.e. an address decoder 14, and the second electrodes, i.e. the data electrodes, for applying data signals for marginal display 23 are also designated by the address decoder 14.
  • column data 16 are controlled by a CPU 15 and supplied to the data/margin drive circuit 13 so as to effect an image display in the image display region 11 and provide a uniformly bright or dark optical state at the marginal region 11B.
  • Figure 2 illustrates a matrix electrode structure disposed on the liquid crystal display panel 11.
  • the image display region 11A in the liquid crystal display panel or picture area 11 pixels formed at the intersections of the first electrodes, i.e. the scanning electrodes 21, and the second electrodes, i.e. the data electrodes 22, are arranged in X rows and Y columns (X: number of scanning electrodes and Y: number of data electrodes), and in the marginal region(s) 11B, pixels formed at the intersections of the scanning electrodes 21 and the electrodes for marginal display 23 are arranged.
  • the number of the electrodes for marginal display 23 should be determined so as to provide the marginal region 11B with an appropriate width which may be several milli-meters to several centimeters.
  • a ferroelectric liquid crystal is disposed so as to provide a bright state (L) and a dark state (D) through application of driving signal waveforms as shown in Figure 3.
  • a scanning selection period in which a scanning selection signal is to be applied for selection of a scanning electrode
  • a scanning selection signal including a sub-period T1 and a sub-period T2
  • the pixels on a selected scanning electrode are simultaneously cleared into a dark optical state ("D" or black “B") in the period T1 and a pixel selected therefrom is selectively switched into a bright optical state ("L” or white “W”), while the other non-selected pixels retain the dark optical state to effect writing on a scanning electrode.
  • cross nicol polarizers may be adjusted to set the optical state in the period T1 to be a dark state.
  • the frequency of the field scanning may be set to 20 Hz or higher, preferably 30 Hz or higher.
  • the image display region 11A an image is displayed depending on given data signals applied to the data electrodes 22. Further, the electrodes 23 for marginal display are controlled so as to provide a bright (white) optical state uniformly at the pixels in the marginal region 11B while not shown in the figure.
  • Figure 5 is a waveform diagram showing another set of driving signal waveforms used in another driving embodiment which is the same as the one explained with reference to Figure 3 except that different waveforms of scanning selection signal and data signals are used (and also the order of data signals is arbitrary).
  • data signals applied to the electrodes for marginal display are also shown.
  • Figure 6 shows another embodiment of a matrix electrode structure for use in the present invention.
  • an electrode for marginal display 23 having a larger width (preferably, several milli-meters to several centi-meters) than the width (generally 100 - 500 microns) of a data electrode 22,is used as electrodes W1 and W2 in the marginal regions 11B.
  • the number of terminals can be remarkably decreased as compared with the embodiment shown in Figure 2, whereby the IC designing for the data/margin drive circuit can be simplified.
  • a voltage signal having a duration T x which is longer than a maximum pulse duration T D of a data signal may be used in synchronism with a scanning selection signal.
  • a representative driving waveform example for this embodiment is shown in Figure 7.
  • the scanning electrodes 21 and data electrodes 22 are driven similarly as in the embodiment shown in Figure 5, but a voltage signal applied to an electrode for marginal display 23 has a pulse duration T x which is 3/2 times a maximum pulse duration T D of a data signal I1, I2 ...
  • T x a pulse duration which is 3/2 times a maximum pulse duration T D of a data signal I1, I2 ...
  • Reference numerals 81a and 81b denote substrates (glass plates) on which a transparent electrode of, e.g., In2O3, SnO2, ITO (indium-tin-oxide), etc., is disposed, respectively.
  • a liquid crystal of an SmC*-phase in which liquid crystal molecular layers 82 are oriented perpendicular to surfaces of the glass plates 81a and 81b is hermetically disposed therebetween.
  • a full line 83 shows liquid crystal molecules.
  • Each liquid crystal molecule 83 has a dipole moment (P ⁇ ) 84 in a direction perpendicular to the axis thereof.
  • liquid crystal molecules 83 When a voltage higher than a certain threshold level is applied between the electrodes formed on the base plates 81a and 81b, a helical or spiral structure of the liquid crystal molecule 83 is unwound or released to change the alignment direction of respective liquid crystal molecules 83 so that the dipole moments (P ⁇ ) 84 are all directed in the direction of the electric field.
  • the liquid crystal molecules 83 have an elongated shape and show refractive anisotropy between the long axis and the short axis thereof.
  • the liquid crystal cell when, for instance, polarizers arranged in a cross nicol relationship, i.e., with their polarizing directions crossing each other, are disposed on the upper and the lower surfaces of the glass plates 81a and 81b, the liquid crystal cell thus arranged functions as a liquid crystal optical modulation device of which optical characteristics vary depending upon the polarity of an applied voltage.
  • the helical structure of the liquid crystal molecules is released without application of an electric field whereby the dipole moment assumes either of the two states, i.e., Pa in an upper direction 94a or Pb in a lower direction 94b thus providing a bistability condition, as shown in Figure 9.
  • an electric field Ea or Eb higher than a certain threshold level and different from each other in polarity as shown in Figure 9 is applied to a cell having the above-mentioned characteristics, the dipole moment is directed either in the upper direction 94a or in the lower direction 94b depending on the vector of the electric field Ea or Eb.
  • the liquid crystal molecules are oriented to either a first orientation state 93a or a second orientation state 93b.
  • the response speed is quite fast.
  • Second is that the orientation of the liquid crystal shows bistability.
  • the second advantage will be further explained, e.g., with reference to Figure 9.
  • the electric field Ea is applied to the liquid crystal molecules, they are oriented in the first stable state 93a. This state is stably retained even if the electric field is removed.
  • the electric field Eb of which direction is opposite to that of the electric field Ea is applied thereto, the liquid crystal molecules are oriented to the second orientation state 93b whereby the directions of molecules are changed. Likewise, the latter state is stably retained even if the electric field is removed.
  • the liquid crystal molecules are placed in the respective orientation states.
  • the thickness of the cell is as thin as possible and generally 0.5 to 20 microns, further preferably 1 to 5 microns.
  • ferroelectric chiral smectic liquid crystals may be most suitably used, of which liquid crystals in chiral smectic C phase (SmC*) or H phase (SmH*) are particularly suited.
  • These ferroelectric liquid crystals may be those described in, e.g., U.S. Patent Publications US-A-4613209, US-A-4614609, US-A-4622165, etc.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Liquid Crystal Display Device Control (AREA)
  • Liquid Crystal (AREA)
  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)

Claims (7)

  1. Appareil d'affichage à cristal liquide, comprenant:
    un dispositif (11) à cristal liquide comprenant un groupe de premières électrodes (21), un groupe de secondes électrodes (22, 23) coupant lesdites premières électrodes (21), et un cristal liquide ferroélectrique passant dans un état d'orientation en réponse à un champ électrique d'une polarité et dans un autre état d'orientation en réponse à un champ électrique de l'autre polarité, disposé entre ledit groupe de premières électrodes (21) et ledit groupe de secondes électrodes (22, 23) de façon à former une zone d'image comprenant un pixel à chaque intersection desdites premières et secondes électrodes (21, 22, 23), et
    des moyens d'attaque (12, 13, 13A, 13B) pour appliquer séquentiellement un signal de sélection de balayage auxdites premières électrodes (21) et pour appliquer simultanément des signaux de données auxdites secondes électrodes (22, 23),
    caractérisé en ce que
    lesdits moyens d'attaque (12, 13, 13A, 13B)
    - appliquent séquentiellement ledit signal de sélection de balayage (S₁ à Sx) auxdites premières électrodes (21) pour effectuer un balayage entrelacé avec un facteur d'entrelacement de N+1, N étant un entier positif, de telle sorte que ledit signal de sélection de balayage soit appliqué toutes les (N+1)èmes électrodes au cours d'une série de balayages afin de former une image en N+1 séries de balayages, et
    - appliquent simultanément lesdits signaux de données (I₁ à Iy, W₁ à W₆) en synchronisme avec ledit signal de sélection de balayage (S₁ à Sx) à la totalité ou à une partie prescrite desdites secondes électrodes (22, 23) de façon à former en premier lieu un état sombre (D) sur ladite totalité ou une partie prescrite desdits pixels sur l'une particulière desdites premières électrodes (21) puis former un état clair (L) sur un pixel sélectionné parmi ladite totalité ou partie prescrite des pixels sur ladite particulière desdites premières électrodes (21) en fonction dudit signal de sélection de balayage (S₁ à Sx),
    l'appareil étant en outre caractérisé par des moyens (14) pour commander lesdits signaux de données (I₁ à Iy, W₁ à W₆) de façon qu'un nombre prescrit de secondes électrodes (23) de droite ou de gauche soit désigné parmi ledit groupe de secondes électrodes (22, 23), et que ledit nombre prescrit désigné de secondes électrodes (23) reçoive des signaux de données (I₁ à Iy, W₁ à W₆) de façon à former en premier lieu un état sombre, puis à former un état clair à l'emplacement des pixels se trouvant sur ladite première électrode particulière (21), ce qui permet de former un état clair sur tous les pixels se trouvant auxdites intersections entre lesdites premières électrodes (21) et ledit nombre prescrit désigné de secondes électrodes (23).
  2. Appareil selon la revendication 1, caractérisé en ce que ledit cristal liquide ferroélectrique bistable est un cristal liquide smectique chiral.
  3. Appareil selon la revendication 2, caractérisé en ce que ledit cristal liquide smectique chiral présente une structure d'alignement moléculaire non hélicoïdal.
  4. Appareil selon l'une quelconque des revendications précédentes, caractérisé en ce que l'application dudit signal de sélection de balayage (S₁ à Sx) pour un balayage entrelacé est effectuée à une cadence de 20 séries de balayages par seconde ou davantage.
  5. Appareil selon l'une quelconque des revendications précédentes, caractérisé en ce que ledit nombre N est un entier de 1 à 7.
  6. Appareil selon l'une quelconque des revendications précédentes, caractérisé en ce que ledit moyen (14) de commande comporte des moyens pour désigner un nombre prescrit de secondes électrodes (23) de droite ou de gauche.
  7. Appareil selon l'une quelconque des revendications précédentes, caractérisé en ce que ledit nombre prescrit de secondes électrodes (23) de droite ou de gauche est réalisé sous la forme d'une seconde électrode (23) de droite ou de gauche plus large qui présente un plus grande largeur que les autres secondes électrodes (22).
EP89112877A 1988-07-14 1989-07-13 Appareil d'affichage à cristaux liquides Expired - Lifetime EP0350934B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP63176591A JP2651204B2 (ja) 1988-07-14 1988-07-14 液晶装置の駆動法
JP176591/88 1988-07-14

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EP0350934A2 EP0350934A2 (fr) 1990-01-17
EP0350934A3 EP0350934A3 (fr) 1991-08-14
EP0350934B1 true EP0350934B1 (fr) 1995-07-05

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US (2) US5124820A (fr)
EP (1) EP0350934B1 (fr)
JP (1) JP2651204B2 (fr)
DE (1) DE68923327T2 (fr)

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US4701026A (en) * 1984-06-11 1987-10-20 Seiko Epson Kabushiki Kaisha Method and circuits for driving a liquid crystal display device
JPH0750268B2 (ja) * 1985-07-08 1995-05-31 セイコーエプソン株式会社 液晶素子の駆動方法
GB2185614B (en) * 1985-12-25 1990-04-18 Canon Kk Optical modulation device
US4770502A (en) * 1986-01-10 1988-09-13 Hitachi, Ltd. Ferroelectric liquid crystal matrix driving apparatus and method
JPS63116128A (ja) * 1986-11-04 1988-05-20 Canon Inc 光学変調装置
US4901066A (en) * 1986-12-16 1990-02-13 Matsushita Electric Industrial Co., Ltd. Method of driving an optical modulation device
JPS63225295A (ja) * 1987-03-14 1988-09-20 シャープ株式会社 液晶表示装置
JP2651204B2 (ja) * 1988-07-14 1997-09-10 キヤノン株式会社 液晶装置の駆動法

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DE68923327T2 (de) 1995-12-07
EP0350934A3 (fr) 1991-08-14
JPH0225834A (ja) 1990-01-29
US5124820A (en) 1992-06-23
DE68923327D1 (de) 1995-08-10
US5353137A (en) 1994-10-04
EP0350934A2 (fr) 1990-01-17
JP2651204B2 (ja) 1997-09-10

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